-LRB- CNN -RRB- -- We each spend an average of three years of our lives sitting on them , King George II of Great Britain died while on his in 1760 and 2.5 billion people still do not have access to one .

The humble lavatory is the unlikely subject of global celebration on Monday , as one of the world 's most essential inventions but one that too many people still struggle without .

Although many of us tend to take ours for granted , campaigners hope that World Toilet Day 2012 will draw attention to what they 're calling the `` global sanitation crisis , '' with over a third of people worldwide living without a clean and private place to go .

This means that one in three people still have to defecate in the open , using fields or bushes , rivers , railway lines or roadsides , or simply a plastic bag . Others use unsanitary latrines or disease-ridden and foul-smelling buckets .

The majority of those without access to a toilet live in sub-Saharan Africa or Asia , with over half of people in Asia not having proper sanitation , according to the UK-based charity , WaterAid .

Ajara lives in a slum in the city of Gwalior in the Madhya Pradesh province of India . She told WaterAid how people in her community have to defecate on a nearby hilltop .

`` There are no trees and privacy at the moment and so we have to wait until night to go there . It 's difficult for old people to go and it 's hard to go at night . It 's also hard for grown-up girls because of the risk of sexual attack , '' Ajara said .

This World Toilet Day , international aid agencies are highlighting the particular risks to women of poor access to toilets . WaterAid says women are most vulnerable because they 're not only exposed to disease , but also have additional shame , harassment and risk of attack when they go out in the open .

Sandimhia Renato in Mozambique described to WaterAid how she has to cross a very dangerous bridge every time she goes to the bush to defecate .

`` I think it takes 15 minutes to get to the bridge , '' Renato says . `` I come here once a day , between 4 and 5 pm . At night it is very dangerous . People get killed . A woman and a boy were killed with knives . One woman I know of has been raped . ''

But it 's not just the shame and inconvenience of having no private place to go to the toilet , but a huge public health issue .

When you consider that one gram of faeces can contain 10 million viruses , one million bacteria , one thousand parasite cysts and one hundred worm eggs -LRB- according to UNICEF -RRB- you can see why open defecation is so harmful to a community 's health . Without a sewerage system to remove human waste and make it safe , cholera , typhoid and other infectious diseases spread quickly .

The United Nations says more than 2.7 million people die each year due to lack of sanitation . With diarrhoeal diseases killing more young children in developing countries than HIV/AIDS , malaria and measles put together , it 's the second biggest cause of death in under fives , according to the World Health Organization .

Tackling it , says the World Bank 's Water and Sanitation Program , is extremely cost effective . It estimates that poor sanitation costs African countries around $ 5.5 billion a year and $ 53.8 billion in India is lost through associated economic impacts .

The program 's study of 18 African countries found that even the time it takes people to find a discrete location to use the toilet accounted for almost $ 500 million in economic losses . That 's before you examine the cost of healthcare , premature deaths and lost workdays due to illness .

In fact , according to the World Toilet Day organization , every dollar invested in sanitation yields a return of five dollars . Its message is that the solution to the global sanitation crisis lies not in any miraculous technological breakthroughs but in stronger political leadership and a commitment to invest in sanitation infrastructure and education .

Mahatma Gandhi for one seemed to recognized the value of the toilet to humanity when he said `` Sanitation is more important than independence . '' Campaigners for World Toilet Day will be hoping that these words resonate with today 's leaders .

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World Toilet Day highlights plight of 2.5 billion people who do n't have access to basic sanitation

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Charity focusing on dangers for women who must defecate on open ground

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The situation causes shame for millions and also leaves them open to attack

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Lack of basic sanitation costs Africa $ 5.3 billion and India $ 53.8 billion according to World Bank